Assassination Classroom S1

An immensely powerful, alarmingly whimsical creature dubbed Koro Sensei vows to blow up the Earth, having already vaporized a sizeable chunk of the moon. Governments have attempted to kill him, naturally, but shrink at his ungodly speed and fetish for cleanliness. Mysteriously eager to teach a class of Junior High children in the interval before Earth's demise, Koro Sensei gladly allows himself to be shot at, stabbed, suicide bombed and otherwise plotted against by a selection of government subsidized students, for reasons all his own. Nagisa, a shy, insecure boy with a history of disappoint, finds himself torn: consent to perish along with everyone else by graduation, in exchange for a phenomenal teacher --or kill his bizarre mentor to save the world?